//: Playground - noun: a place where people can play

import UIKit
import Foundation

var void: Void?

class abc {
    var conven = "ssdas"
}

extension abc {
    var vvv: String {
        set {
            objc_setAssociatedObject(self, &void, newValue, .OBJC_ASSOCIATION_COPY_NONATOMIC)
        }
        get {
            return objc_getAssociatedObject(self, &void) as! String
        }
    }
}

var view = abc()
view.vvv = "啥都"
view.vvv

let ddd = CGFloat.leastNormalMagnitude
ddd
